FIG. 1 illustrates a typical construction 100 of a cladding construction system of a concrete roof deck 102. A cement sand base 104 is formed over the roof deck 102, the base 104 being screed to form a slope or slope-to-fall gradient to create a drainage fall into a drain 106 and downpipe 108. A waterproof membrane 110 is laid over the cement sand base 104, interrupted only by downpipe 108, and extending a height 112 of 300 mm (0.98 feet) up the inside surface of walls 114. Where the deck 102 meets some walls 114, the transition of the waterproof membrane from the horizontal surface to the vertical surface may be effected by use of waterproof filler such as poly foam 116. A thermal insulating layer 118 is constructed on top of the membrane 110, the layer 118 comprising extruded polystyrene insulation board of 50 mm (2 inches) thickness. A separation fleece layer 120 overlies the thermal insulating layer 118. Finally an overlying protective screed concrete layer 122 of 75 mm (2.9 inches) thickness is provided, comprising 4.5 m (4.9 yards) by 4.5 m (4.9 yards) panels separated by joints filled with bituminous compound. Plastering 124 is applied to walls 114.
The thermal insulating material 118 reduces heat transfer through the concrete roof deck 102 into the building below. The protective cement screed 122 protects the thermal insulating material 118 and the waterproofing membrane 110, and bears the human traffic on the roof deck. Such a construction 100 is constructed in-situ on site, with an expansion joint provided at regular intervals.
Construction 100 suffers from a range of problems. The expansion joints in concrete screed layer 122 are a weak point in the construction and a source of leaks. Residual water becomes lodged between the thermal insulating material 118 and the waterproofing membrane 110 after rain. When exposed to heat from the sun, the water expands and evaporates, exerting pressure on the thermal insulating material 118 which in turn exerts pressure onto the protective screed concrete 122. Both the protective screed concrete 122 and thermal insulating material 118 will generally crack due to such stress, leading to leakage and/or “sickness” in the construction 100.
A further problem is that on site cladding construction makes quality control difficult, can cause damage to the waterproofing system, and is subject to the vagaries of inclement weather during construction leading to time delay. In addition, mixing, handling and/or applying concrete slurry on site can be messy and laborious.
Still further, in the event that maintenance is required to the underlying roof deck 102, waterproofing membrane 110 and/or components of the built-up waterproofing system 104, 118, 120, 122, the protective screed 122 and some or all underlying layers need to be destructively removed such as by being cut away, effectively destroying the construction 100. The entire process of building up the waterproofing system must then be repeated to re-establish a waterproof cladding.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.